The record label of the South Korean rock band CNBLUE filed an anti-defamation lawsuit in Seoul Central District Court Thursday against the group Crying Nut, on the artists' behalf.

In the suit, FNC Entertainment charges that Crying Nut deliberately spread lies about CNBLUE, charging that the group covered their original song "Deadly Offside" illegally before the bands had experienced their day in court.

"Crying Nut has been claiming that CNBLUE committed an infringement of their copyrights," an FNC Entertainment representative told the publication Soompi on Monday.

"Though the merits of their claim is still under proceeding, they have been talking about it as if it were the truth...all CNBLUE did, who had only debuted six months ago at the time, was to sing with the instrumental track the station said it prepared."

Crying Nut filed a copyright infringement lawsuit against CNBLUE back in February.

The lawsuit charged that CNBLUE had used Crying Nut's version of the song in June of 2010 on the Mnet program "M! Countdown," and passed it off as their own playing.

The performance of "Deadly Offside," which was the Team Korea theme for the 2002 World Cup, was allegedly recorded and released on DVD in Japan.

Back in February, a FNC Spokesperson defended the band, claiming the entire debacle was the fault of the "M! Countdown" production staff.

"The production team of 'M Countdown' asked CNBLUE to sing 'Deadly Offside.' The production team had stated that they would provide the background music for the song," the rep explained.

"They wanted CNBLUE to sing it because the 2010 South African World Cup was going on. At the time CNBLUE was a rookie group and they could not say no...of course we thought the music source was just background music and CNBLUE performed for 'M Countdown.'"

The FNC Entertainment spokesperson added that the band had no control over the fact their performance of "Deadly Offside" was released on DVD.

"The DVD in question was released by a broadcasting company that had the rights to the performance," the rep said.

"The DVD itself was created without any authorization from CNBLUE. We are also victims in this situation."

The label also issued an official apology on their website.

"It was our fault for putting up the singers on stage in such a frantic live stage without checking if the background music was being used legally or not," the label's apology read.

"We are also think that it is a shame that DVDs were sold of the performance and we weren't able to proactively remedy that situation. Instead of the CNBLUE members, we apologize to their seniors Crying Nut."

The apology apparently wasn't enough for Crying Nut.

"Despite the apology it is very difficult to erase a feeling of bitterness," a representative for the band wrote in an official response to the FNC apology.

"In articles [the members of CNBLUE] have stated that they would try and ensure that something like this would not happen again. However, there are no statements regarding on how they will go about ensuring that."

And what do the members of Crying Nut plan to do with the money if they win the lawsuit?

"We will use the money that we are going to receive from the lawsuit and help improve the indie music scene by giving the money as charity," the statement read.